Vascular dizziness and transcranial Doppler ultrasonography.

Dizziness as defined herein will include an illusion of motion caused by various degrees of ischemia to the vestibular pathway or its interconnecting pathways. "Syndrome," such as the lateral medullary syndrome, denotes a macroinfarct, while a microinfarct or an area of incomplete infarct (where there may develop an incomplete degeneration of the neural tissue secondary to the arteriolar microatheromatous stenosis) may cause only one neurologic deficit, such as dizziness per se as the only symptom. However, the latter may presage a larger and more debilitating neurologic deficit. The transcranial Doppler, used to track sequentially the larger basal arteries of the brain, specifically the vertebrobasilar arterial system, is an addition to noninvasive diagnostic methods of separating vascular problems from other causes of dizziness.